Texoma, in north-central Texas, is the newest addition to the state's eight-strong list of AVAs. Officially recognized in January 2006, it covers 233,600 acres (94,500ha), making it the second largest in Texas behind the vast Texas Hill Country.
Named after Lake Texoma, the AVA is bordered in the north by the Red river. It runs west–east en route from the Texas Panhandle (where it rises just west of the Texas High Plains) to the Mississippi, of which it is a major tributary. It also marks the border between Texas and Oklahoma.
Texoma's soils are convincingly dominated by silty loam and clay – not surprising, given its location along the alluvial plains of the river. The elevation here ranges from 425 to 1320ft (130–402m), with corresponding temperature and soil-type variations.
The continental climate of Texoma is typical of Texas, with cold winters (falling to 14F/-10 C) and warm summers. Diurnal temperature variation is a key feature, being more pronounced in the spring and winter. Spring frosts are a regular risk for Texoma's vineyards, making the region better suited to later-budding varieties such as Cabernet Sauvignon. However, many wineries take a chance with popular, earlier-ripening grapes such as Merlot, Pinot Noir and Chardonnay. The area all along the Red river is home to various native American vine varieties – a fact which earned it the epithet 'grape paradise' from the 19th-century ampelographer T.V Munson.
It was within the Texoma area, in the 1880s, that Munson pioneered a workable solution to the phylloxera epidemic which was ravaging the world's vineyards. A Texas-born, Kentucky-based student of viticulture, Munson settled near Denison in 1876 and established his own vineyard. He ran this not only as a nursery business but also as a part of his lifelong studies. Using these vines, he carried out various grafting experiments and eventually discovered that grafting Vitis vinifera scions onto American rootstocks resulted in phylloxera-resistant vines. Munson's efforts earned him the Ordre du Merite Agricole from the French government, a title first awarded to Louis Pasteur just five years earlier.
